A randomized, open-label, multicenter phase IIIB comparative 24 week study with a treatment extension to 48 weeks in treatment naive and NRTI experience patients. The randomization is stratified by baseline viral load and prior antiretroviral treatment. Study medications will be administered for 24 weeks. Patients will continue on treatment to a common study closure date to 48 weeks of treatment and will be followed according to the Schedule of Assessments. The study will begin in July 1997 and will continue until 275 patients have been enrolled in each arm. Enrollment is expected to be completed by October 1997 and the study will be completed by November 1998.